A method, a computer program and a system for ultrasonic inspecting of objects is provided. The method comprises positioning (103) a measuring device (11) comprising a plurality of transducers (12) on the inspected object (20) and performing a number of test signal acquisitions (103). Each acquisition includes using one transducer to induce an ultrasonic signal into the test object, and using at least one other transducer to receive an ultrasonic test signal. The inspecting further comprises determining (105, 205) the influence of contact surface variations between each test signal and a reference signal; compensating (106, 206) the full test signal for the contact surface variations; and determining (109) a residual signal. The system comprises a computing device (30), and a measuring system (13) communicatively connected to the computing device (30). The measuring system (13) includes an ultrasound unit (19) and a measuring device (11) provided with a plurality of transducers (12). The computing device (30) comprises a calibrator (303) to determine (105, 205) the influence of contact surface variations, and compensate (106, 206) the test signal. The computing device (30) comprises a residual calculator (304) to determine (109) the residual signal.

A gas sensor array system includes a gas sensing chamber, a sensor array provided within the gas sensing chamber and including a plurality of gas sensing components each gas comprising a gas adsorbing material (such as an MOF material), and wherein the gas adsorbing material is different for each of the plurality of gas sensing components. The system also includes a gas source for supplying a gas sample to be measured, a gas pressure regulator structured and configured for selectively adjusting a pressure of the gas mixture suppled to the gas sensing chamber, and a controller structured and configured to (i) control the gas pressure regulator to selectively adjust the pressure of the gas sample to a number of pressure levels, and (ii) while the gas sample is provided at each pressure level, make a gas parameter measurement using outputs of one or more of the gas sensing components.

A method includes receiving a gas or gas mixture through a flow sensor. A flow velocity, volumetric, or mass flow are determined. The method also includes determining a sound velocity of the gas or gas mixture by an ultrasonic sensor. A density of the gas or gas mixture is correlated from the sound velocity. The method also includes positioning a microthermal sensor in an area with less flow or no flow of the gas or gas mixture. A thermal conductivity and thermal diffusivity of the gas or gas mixture at the one or more temperatures is determined. The method also includes connecting a processor to the microthermal sensor to calculate an energy of the gas or gas mixture based on a calorific value, the temperature and the volume or mass flow. Specific quantities for gas quality are correlated.

A non-destructive testing device with an ultrasonic transducer array inspects objects carrying a fluid. Ultrasound reflections are stored in the device and processed to create images of the object. A processor estimates the speed of sound of the fluid by trying values for the sound speed and for each value: makes images from the reflections, calculate geometric parameters for the object from the images, and calculate a metric for how much the parameters vary. The estimated speed of sound is associate with the optimized metric.